This has nothing to do with SSBM. I'd name it "Sonic Battle" but there's a video-game with that name. I'd name it Sonic Brawl if I didn't name other game (now locked) with that name.

Ok, Here is how it works. There is a list of characters. The first poster puts two in battle. The second decides who wins, and put two other in battle. The third decides who wins and put two other in battle, and so on. Ex:P1:SonicShadowSilver